The present invention relates, in general, to an optical switch, and more particularly to an optical switch utilizing electrostatic deformation of an optically transparent elastomer.
In optical systems it is important to have a low cost and reliable means of switching an optical signal between various destinations. Applications of an optical switch include selection of a computer terminal or a computer node on an optical local area network, selection of between multiple programming sources on a cable TV distribution system, and routing of optical signals in a broadband switched communications network. Optical transmission of signals provides many advantages over other methods including a unique combination of wide signal bandwidth, low crosstalk between different signals, and almost total immunity from electromagnetic interference. It is extremely important that any switching method not compromise these advantages.
Past approaches to optical switches have included the use of electro-optical effects for switching. These approaches induce a refractive index change by carrier injection into various silicon, gallium arsenide or lithium niobate based structures. Electro-optical effects are inherently weak effects which require a long common path length and small cross section for the switch. This produces a high level of crosstalk between switch elements as well as excessive signal loss along the desired path. In addition the materials used and the complexity of the structures make these approaches expensive to produce. There remains a need for a low cost and reliable method to switch optical signals which does not compromise the unique advantages of optical signal transmission.